Can you keep driving?
Can you keep driving?
Stop driving if any of these apply
- !The check-engine light is flashing.
- !The engine is running badly enough that traffic safety or engine damage becomes a concern.
What to check first
Step-by-step checks
- 1
Free - no tools
Check for pedal or throttle response that feels inconsistent, stuck, or delayed
- 2
Free - no tools
Inspect the connector and wiring for the throttle body or pedal sensor that the code points to
- 3
Basic tool needed
Look for other throttle, pedal, or airflow codes that might point to the same circuit path
- 4
Basic tool needed
If scan data is available, compare commanded position with the actual sensor reading
- 5
Basic tool needed
If the fault appears after recent work, verify the connector and harness were not left loose or strained
If the code returns
- -If the signal is missing, jumps, or does not agree with commanded position, circuit testing becomes more important.
- -If the reading is unstable only when the harness is moved, wiring deserves a closer look.
- -If the code returns after a throttle-body or pedal repair, verify the connector pins and reference circuits again.
Background
What this code means
P0124 is a generic OBD-II throttle-position or accelerator-pedal signal code.
These codes usually point to a sensor, connector, or signal-path issue rather than a simple tune-up item.
Diagnosis
Common causes
Throttle or pedal sensor fault
The signal itself may be out of range or unstable.
Connector or harness issue
A loose plug, corroded pin, or damaged wire can create the code.
Throttle body contamination
Carbon buildup can affect the sensor or throttle movement on some systems.
Reference or ground problem
The sensor may be fine but the circuit feeding it is not.
Avoid these mistakes
What not to do
- xDo not replace major parts before checking the simple causes first.
- xDo not ignore a flashing check-engine light or obvious drivability symptoms.
Parts
Parts that may need replacing
See also
Related OBD codes
Source notes
Generic OBD-II (SAE J1979 / ISO 15031-5). P0124 was expanded around common intermittent throttle-position faults, with conservative guidance focused on signal dropouts, wiring issues, and connector problems.
This guide is written as a generic multi-make reference, so bulletin history, sensor locations, and repair order can still change by manufacturer and engine family.
This is generic OBD-II guidance and should not override vehicle-specific service information. Exact diagnosis and repair steps vary by make, engine family, and model year.
Last reviewed: 2026-04-10
Reference: Open reference